Analytical performance, agreement and user-friendliness of six point-of-care testing urine analysers for urinary tract infection in general practice

OBJECTIVE: Various point-of-care testing (POCT) urine analysers are commercially available for routine urine analysis in general practice. The present study compares analytical performance, agreement and user-friendliness of six different POCT urine analysers for diagnosing urinary tract infection in general practice. SETTING: All testing procedures were performed at a diagnostic centre for primary care in the Netherlands. Urine samples were collected at four general practices. PRIMARY AND SECONDARY OUTCOME MEASURES: Analytical performance and agreement of the POCT analysers regarding nitrite, leucocytes and erythrocytes, with the laboratory reference standard, was the primary outcome measure, and analysed by calculating sensitivity, specificity, positive and negative predictive value, and Cohen's κ coefficient for agreement. Secondary outcome measures were the user-friendliness of the POCT analysers, in addition to other characteristics of the analysers. RESULTS: The following six POCT analysers were evaluated: Uryxxon Relax (Macherey Nagel), Urisys 1100 (Roche), Clinitek Status (Siemens), Aution 11 (Menarini), Aution Micro (Menarini) and Urilyzer (Analyticon). Analytical performance was good for all analysers. Compared with laboratory reference standards, overall agreement was good, but differed per parameter and per analyser. Concerning the nitrite test, the most important test for clinical practice, all but one showed perfect agreement with the laboratory standard. For leucocytes and erythrocytes specificity was high, but sensitivity was considerably lower. Agreement for leucocytes varied between good to very good, and for the erythrocyte test between fair and good. First-time users indicated that the analysers were easy to use. They expected higher productivity and accuracy when using these analysers in daily practice. CONCLUSIONS: The overall performance and user-friendliness of all six commercially available POCT urine analysers was sufficient to justify routine use in suspected urinary tract infections in general practice

Analytical performance, agreement and user-friendliness of six point-of-care testing urine analysers for urinary tract infection in general practice

OBJECTIVE: Various point-of-care testing (POCT) urine analysers are commercially available for routine urine analysis in general practice. The present study compares analytical performance, agreement and user-friendliness of six different POCT urine analysers for diagnosing urinary tract infection in general practice. SETTING: All testing procedures were performed at a diagnostic centre for primary care in the Netherlands. Urine samples were collected at four general practices. PRIMARY AND SECONDARY OUTCOME MEASURES: Analytical performance and agreement of the POCT analysers regarding nitrite, leucocytes and erythrocytes, with the laboratory reference standard, was the primary outcome measure, and analysed by calculating sensitivity, specificity, positive and negative predictive value, and Cohen's κ coefficient for agreement. Secondary outcome measures were the user-friendliness of the POCT analysers, in addition to other characteristics of the analysers. RESULTS: The following six POCT analysers were evaluated: Uryxxon Relax (Macherey Nagel), Urisys 1100 (Roche), Clinitek Status (Siemens), Aution 11 (Menarini), Aution Micro (Menarini) and Urilyzer (Analyticon). Analytical performance was good for all analysers. Compared with laboratory reference standards, overall agreement was good, but differed per parameter and per analyser. Concerning the nitrite test, the most important test for clinical practice, all but one showed perfect agreement with the laboratory standard. For leucocytes and erythrocytes specificity was high, but sensitivity was considerably lower. Agreement for leucocytes varied between good to very good, and for the erythrocyte test between fair and good. First-time users indicated that the analysers were easy to use. They expected higher productivity and accuracy when using these analysers in daily practice. CONCLUSIONS: The overall performance and user-friendliness of all six commercially available POCT urine analysers was sufficient to justify routine use in suspected urinary tract infections in general practice

Data from: Analytical performance, agreement and user-friendliness of six point of care testing urine analysers for urinary tract infection in general practice.

Objective: Various point-of-care testing (POCT) urine analysers are commercially available for routine urine analysis in general practice. The present study compares analytical performance, agreement and user-friendliness of six different POCT urine analysers for diagnosing urinary tract infection in general practice. Setting: All testing procedures were performed at a diagnostic centre for primary care in the Netherlands. Urine samples were collected at four general practices. Primary and secondary outcome measures: Analytical performance and agreement of the POCT analysers regarding nitrite, leucocytes and erythrocytes, with the laboratory reference standard, was the primary outcome measure, and analysed by calculating sensitivity, specificity, positive and negative predictive value, and Cohen's κ coefficient for agreement. Secondary outcome measures were the user-friendliness of the POCT analysers, in addition to other characteristics of the analysers. Results: The following six POCT analysers were evaluated: Uryxxon Relax (Macherey Nagel), Urisys 1100 (Roche), Clinitek Status (Siemens), Aution 11 (Menarini), Aution Micro (Menarini) and Urilyzer (Analyticon). Analytical performance was good for all analysers. Compared with laboratory reference standards, overall agreement was good, but differed per parameter and per analyser. Concerning the nitrite test, the most important test for clinical practice, all but one showed perfect agreement with the laboratory standard. For leucocytes and erythrocytes specificity was high, but sensitivity was considerably lower. Agreement for leucocytes varied between good to very good, and for the erythrocyte test between fair and good. First-time users indicated that the analysers were easy to use. They expected higher productivity and accuracy when using these analysers in daily practice. Conclusions: The overall performance and user-friendliness of all six commercially available POCT urine analysers was sufficient to justify routine use in suspected urinary tract infections in general practice

Influence of duration and dose of metformin on cobalamin deficiency in type 2 diabetes patients using metformin

Metformin use is associated with cobalamin (vitamin B12) deficiency. However, the influence of both duration and dose of metformin is unclear. Studies using holotranscobalamin, a marker for cellular cobalamin deficiency, are scarce. We therefore investigated the prevalence of cobalamin deficiency in type 2 diabetes patients using both markers, and its relation with duration and dose of metformin use. This cross-sectional study among 550 type 2 diabetes patients using metformin (mean daily dose 1,306 mg; mean duration 64 months) was conducted in four primary care centers in Utrecht, the Netherlands. Cobalamin and holotranscobalamin concentrations were measured at the annual diabetes check. Detailed information on metformin use and confounding variables was collected from medical records. The prevalence of a cobalamin deficiency was 28.1 %, while a holotranscobalamin deficiency occurred in 3.9 % of the patients. Adjusting for multiple confounders, a 1 mg/day increase in daily metformin dose was associated (p < 0.001) with 0.042 (95 % CI −0.060, −0.023) decrease in cobalamin concentrations. Similarly, a 10 g increase of cumulative metformin dose was associated (p = 0.006) with −0.070 (−0.12, −0.021) lower cobalamin concentrations after adjustment for confounders. Duration of metformin use was not associated with cobalamin concentrations after multivariable adjustment. Similar results were observed for holotranscobalamin. Cobalamin deficiency occurs frequently among diabetes patients using metformin. A higher daily and cumulative doses of metformin were strongly associated with lower cobalamin and holotranscobalamin concentrations, while duration was not. It is thus important to account for metformin dose in recommendations for screening for cobalamin deficiency

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